Vallicella on Immortal Souls

At his Substack Philosophy in Progress, my old buddy Bill Vallicella engages with my book Immortal Souls: A Treatise on Human Nature.  Bill kindly opines: “[It] may well be the best compendium of Thomist philosophical anthropology presently available.  I strongly recommend it.”  All the same, he has doubts about the compatibility of two of the books key themes: the Aristotelian hylomorphic conception of the soul as the form of the body, and the continued existence of any particular individual’s soul after the death of his body.  Let’s take a look at his objection.

Hylomorphism in brief

Longtime readers of this blog or of my books will be familiar with the Aristotelian-Thomistic conception of physical substances as composites of form and matter, where (to a first approximation) matter is the stuff out of which such a substance is made and form is what organizes that stuff in a way that allows it to manifest its characteristic properties and powers.  More precisely, it is substantial form that does so.  And the soul is a substantial form of the kind that gives a physical substance the distinctive properties and powers of a living thing.

Matter, on Aquinas’s account, is what makes it possible for there to be more than one instance of any species of physical substance (using “species” here in the traditional broad metaphysical sense, not the narrower biological sense).  Different lumps of iron all have the same basic nature, as do different oak trees and different poodles.  But if they have the same nature, how can they be different substances?  The answer is that there are different bits of matter which have all taken on the same nature.  Matter is in this way the “principle of individuation” of physical substances. 

When the matter of a purely physical substance loses its substantial form, that particular substance goes out of existence altogether.  For example, when you chop down an oak tree and burn it in the fireplace, that particular oak tree is gone.  The matter out of which it is made persists, but it has taken on an entirely different form, the form of ash.  The substantial form of an oak tree is no longer present in it (even though there are, of course, other oak trees, and they have such a substantial form).

Now, Aquinas thinks of angels as substances that are purely intellectual in nature, and thus (since he takes the intellect to be incorporeal) to be immaterial substances.  Because they are immaterial, there is no way to individuate one member of an angelic species from another.  There can still be different species of angel, but each will have exactly one member.  Hence there are as many angelic species as there are angels.

The human intellect, like angelic intellects, is incorporeal.  How, then, can there be more than one member of the human species?  The answer, for Aquinas, is that while human beings are not purely corporeal substances (unlike iron, oak trees, and poodles) neither are they purely incorporeal substances (as angels are).  A human being is a unique sort of substance that has both corporeal properties and powers (such as eating, walking, seeing, and hearing) and incorporeal ones (thinking and willing). 

Because human beings are partly corporeal, they can be individuated from one another as different members of the same species.  But because they are partly incorporeal, they do not go out of existence altogether at death.  They carry on as incomplete substances after death, reduced to just their intellectual (and thus incorporeal) operations.  Because every substance has a form, and human beings continue on as incomplete substances, a human being’s form continues on after death.  And since the soul just is the substantial form of a human being, that means that the soul carries on after death.  It no longer manifests the corporeal powers that it would normally give human beings (since, absent the body, there’s no matter for it to inform).  But the incorporeal powers can still manifest. 

Vallicella’s objection

Bill begins his criticism of this view by saying that Aristotelian-Thomistic hylomorphism holds that “substances of the same kind have the same substantial form.”  In the case of human beings, he continues, “since these substances of the human kind have the same form, it is not their form that makes them numerically different… It is the matter of their respective bodies that makes numerically different human beings numerically different.”

But in that case, Bill argues, when the matter of some particular human being goes at death, there is nothing left to individuate him.  Hence there can be nothing of him, in particular, that carries on.  Bill writes:

After death a human person ceases to exist as the particular person that he or she is.  But that is to say that the particular person, Socrates say, ceases to exist, full stop.  What survives is at best a form which is common to all persons.  That form, however, cannot be you or me.  Thus the particularity, individuality, haecceity, ipseity of persons, which is essential to persons, is lost at death and does not survive post mortem.

Bill appears to think that if the Aristotelian-Thomistic view were applied consistently, it would have to say of human beings what it says of iron, oak trees, and poodles.  Just as the particular individual oak tree that you burn in the fireplace is altogether gone (even though there are other oak trees that carry on), so too, after death, is the particular individual human being altogether gone (even though there are other human beings who carry on).

But there are two problems with Bill’s argument.  The first is that it rests on a mistaken conception of substantial form.  The second is that it neglects the crucial difference the Thomist says exists between human beings and every other corporeal substance, which is that human beings have incorporeal intellectual powers.

Let’s consider these points in order.  When Bill says that, for hylomorphism, “substances of the same kind have the same substantial form,” he speaks ambiguously.  That could mean that, while each individual physical substance has its own substantial form, with physical substances of the same species their substantial forms are of the same kind.  That would be a correct characterization of the Aristotelian-Thomistic position, but unfortunately it does not seem to be what Bill means.  He seems to mean instead that there is one substantial form shared by all human beings in common – not one kind of substantial form, but one substantial form. 

But that is not what Aristotelian-Thomistic hylomorphism says, and it is not true.  There are, it seems to me, two ways to read Bill’s claim.  On one reading, the substantial form of human beings is a kind of Platonic Form, and different human bodies are all human because they participate in that same one Form.  The problem with this is that it isn’t an Aristotelian conception of form at all, but a Platonic conception.  A substantial form, for the Aristotelian, isn’t an abstract Platonic object in which a thing participates.  Rather, it is a concrete principle intrinsic to a substance that grounds its characteristic properties and powers.

The other way to read Bill’s characterization of hylomorphism is as holding that human beings share one substantial form in the sense that they are all part of one big substance – humanity considered as something like a single organism, with different individual human beings as analogous to body parts that that organism gains or loses as people are conceived or die.  But this is obviously not Aristotle’s or Aquinas’s view.  They take human beings to be substances, not parts of a substance.  And as substances, each must have his own substantial form.

I think it’s the first of these interpretations (what I’m characterizing as the Platonic one), rather than the second, that Bill has in mind.  But, again, it is a mistaken interpretation.  It just isn’t the case that you, me, and Socrates all share the same one substantial form in the sense Bill’s argument requires.  Rather, you have your own substantial form (and thus soul), I have mine, and Socrates has his. 

The same thing is true of an oak tree.  This oak tree has its own individual substantial form, that oak tree has its own individual substantial form, and so on.  The reason none of them continue after death is that everything an oak tree has or does – and thus every property or power its substantial form gives it – depends on matter.  Hence when the matter goes, there’s nothing left for the form to inform, nothing left for it to be the form of. 

This brings us to the second crucial point, which is that a human being, unlike an oak tree, has properties and powers that do not depend on matter – namely, the intellectual properties and powers.  Hence, a human being is not an entirely corporeal substance, but a partly incorporeal one.  This incorporeal part carries on after the body dies, so that there is in this case (unlike the case of the oak tree) something for the form to continue to be the form of. 

And that is the sense in which the soul carries on beyond the death of the body.  Yes, the soul is the form of the body, because it is the form of a substance that it partially bodily in nature.  But unlike an oak or a poodle, a human being is not entirely bodily in nature, so that there is (as it were) still work for the human soul to do even after the body is gone.

Why does this not make the human soul after death like an angel, the unique member of its own distinct species?  The answer is that the soul was once conjoined to its body and always retains its orientation to that particular body.  An angel without a body is no less an angel for that.  It is complete in its incorporeal mode of existence.  By contrast, a human being without a body (that is to say, a disembodied soul) is less of a human being insofar as it is an incomplete human being.  Incorporeality is normal for an angel, but not for a human being.  This orientation toward matter, which persists even in the absence of matter, suffices to individuate human souls. 

Of course, Bill may raise further objections, to some or all of what I’ve said here.  The point, though, is to indicate why I think the particular objection he raises in his post fails.  (Longtime readers might remember that this issue is in fact a matter of longstanding dispute between Bill and me.  I’ve linked to some earlier posts on the subject below.)

I want to add in closing that I have been reading Bill’s recent book Life’s Path with pleasure and profit, and advise you to do the same.  Bill is among the rare contemporary philosophers who live up to the traditional ideal of producing both solid technical academic philosophical work (as in his superb earlier book A Paradigm Theory of Existence) and insightful moral, political, and other practical reflections accessible to a more popular audience (as in the more recent book).  Read and learn.

Related posts:

Vallicella on hylemorphic dualism

Vallicella on hylemorphic dualism, Part II

Vallicella on hylemorphic dualism, Part III